A typical example of such apparatus is the work platform which supports a fruit picker, where the invention provides for controlled movement and positioning of such platform continuously or intermittently as directed by the picker while he is simultaneously performing fruit location, detachment and disposal tasks. In some instances, the operator may not be positioned on the work station but on the ground or some other point on the machine structure. An example of such use is in pruning in which a remotely controlled articulated cutter can be mounted at the workstation, the operation of positioning the cutter and operating the cutter being carried out by an operator at some other position, for example, on the ground.
In its broadest aspects the present invention is useful in any equipment situation in which it is desired to position a worker and/or other task effectors in various spatial locations to enable them to carry out task operations. Such operations include the fabrication or inspection and repair of mechanical structures, the application, restoration or removal of decorative embellishments, or the transportation placement and retrieval of equipment or materials, and other situations wherein three dimensional positioning of the worker and spatial orientation of the task effectors is necessary. For purposes of the present specification, preferred embodiments of the invention will be described as utilized in a tree crop servicing apparatus, a load manipulator apparatus and a bulk handler apparatus.
Several structures, both mobile and stationary, have been proposed heretofore to elevate and position a worker adjacent to various tree branches in order to facilitate multi-positional tasks such as pruning, pollinating and harvesting tree crops. As an example, fruit pickers are supported on a platform, which may be in the form of a bucket, and the platform be suspended by means of a powered, articulated structure that can be moved to bring the picker into a picking position. It has also been previously proposed that an electro-hydraulic control system be provided for actuating the various members of the support structure in response to the task related positioning of a picker's body and thereby to move the platform in a desired direction and at a desired rate. One such system is described in U.S. Pat. No. 3,384,201. In this example, the platform is mounted on a rectilinear arm configured to provide planer in-and-out movement. This arm is in turn mounted on a vertical lift-boom. Sideways movement of the platform is provided by rotation of the boom. The apparatus has control limitations that make it applicable only to vehicles with support structures that embody rectilinear movement in the vertical plane. The bucket platform's movements are controlled by direct actuation of various electro-hydraulic controls using inputs generated by task related movements of the body of the person on the platform. This restricts the application and adaptability of the apparatus.
In order to optimize man-machine task efficiency in fruit picking and in other extended volume multi-positional tasks, it is essential that movements of the work station be the product of task related directive inputs by the worker utilizing the equipment. Movements of the work station must be quick and accurate and at all times must be closely matched to the natural stimuli-decision-action capabilities of the human operator. Juxtaposed against these platform positioning performance requirements is the fact that the simpler and more efficient movable platform suspension structures are inherently non-linear in their directional and rate responses when driven by general purpose movement actuators. The picker's body actuated control inputs and the relatively complex rectilinear vertical plane platform movement features engineered into the system defined in U.S. Pat. No. 3,384,201 are one approach to meeting these mobile platform performance requirements.
In accomplishing the required level of work platform mobility and situational flexibility there is an even more important requirement. It is that the entire powered structure and its control system embody the highest achievable levels intrinsic operational safety. The difficulties in achieving these fundamental objectives are compounded by the operational environment within which the man-machine system must be able to function. Tree crop service tasks are among the most demanding of these environments. Typically a picker must work continuously from the platform with his principal attention focused on the location, detachment and disposal of the tree crop. His task requires that he move around all of the leaf line surface of each tree with periodic penetrations into the limb structure to collect interior fruits. When his platform mounted product container is filled he must rapidly move to bulk handling containers, avoiding all intervening tree and machine structure, and empty his collector container. He then must rapidly and safely retrace his path back to the current harvesting point.
When the tree crop located within the current work envelope of his machine is harvested, the operator must dock his work station on the machine and move the unit to its next harvesting position. The equipage must be capable of operating on tilled fields, ofttimes crisscrossed by furrows, berms or ditches. It may also be required to be capable of operating in untilled orchard areas, and hillside groves. To transit such terrain it must have a base carriage with excellent traction and low center-of-gravity when in the platform-docked configuration. To insure a full measure of stability under all terrain conditions where the mobile platform may be reasonably expected to operate, the base platform of the assembly may be equipped with a self-leveling outrigger system. Tree crop groves and orchards are usually characterized by rows of trees planted to maximize per acre production. As these trees mature the clear space between the rows narrows, sometimes to the point where the upper limbs begin to intertwine. Even in these narrow and canopy cluttered corridors the machine and its mobile platform must be capable of operating safely and with high task efficiency.
With the foregoing requirements and considerations in mind, one of the primary objectives of the present invention is to provide a greatly improved tri-dimensional mobile work station apparatus; one that is capable of providing full augmentation to an operator's manifold task performance requirements in a dynamic work environment, and also equally able to simultaneously monitor and actively contribute to operational safety on a situational basis.
More particularly it is an object to provide an improved tri-dimensional mobile work station apparatus incorporating a multi-function adaptive control system capable of deriving spatial positioning directives by monitoring operator body positioning, to then condition the response to these directives in a process that takes into account apparatus situational variables and applies a full resident structure of operating criteria, and then to either generate the appropriate platform movement response or intervene in the execution of such directives when established safety or capability determinates would be violated.